Over the past three decades, there has been a progressive acknowledgement of sexual assault as a significant social problem that brings with it a wide range of personal and social consequences. Approximately 693174 cases of child sexual abuse are confirmed in the United States each year (Administration on Children Youth and Families, 2009). Self-report victimization surveys have found that 23% of adults were sexually abused before the age of 18(Fikelhor, 2004). Other researchers’ reviews that estimated that 17%-22% of women and 2%-8% of men have been victims of sexual assault and that over 100000 children are sexually abused each year. The Incidence and Prevalence Survey indicated that 78 sexual assaults take place per hour in our country, because many cases of sexual abuse go unreported due to victim fear shame or loyalty to the abuser, documented reports of sexual assault underestimate the extent of the problem. The majority of sex crimes may go undetected and some sexual offenders admit to committing more sexual assaults than those for which they have been caught. There is no doubt that sexual assault is a serious social problem, and that our society continues to grapple with how to best address this concern.

Rational choice theory

In criminology, the rational choice perspective is a theoretical framework specifically designed to investigate the decision-making of offenders. Criminals decide whether or not to commit a crime by weighting the effort, rewards, and costs involved in alternative courses of action. The making of decisions and choices, however original the process might sometimes be, exhibits a measure of rationality, while forced by limits of time, ability, and the availability of relevant information.

Cornish(1994) considered crime is viewed as a dynamic process influenced by situational factors, offenders are seen as individuals who may improve their decision-making through experience and learn to modify their strategies to commit crimes.

Several researchers have used a rational choice theory to the decision-making sexual offenders. However, these studies have focused on the personal internally driven psychological process (cognitive and affective) of the offender leading to the commission of sexual assault, overlooking the decision-making during the offense in interaction with the immediate situations encountered at the crime scene(Beaurgard & Rossmo,2005；Beauregard, Stone& Proulx ,2008).

Based on a rational choice theory, Beauregard and Leclerc (2007) have interview 69 serial sexual offenders who have committed their crimes against stranger victims. Semi-structured interviews were conducted with offenders in order to identify the rationale behind their actions during the pre-crime phase (premeditation of crime, estimation of risk of apprehension by the offender, and forensic awareness of the offender), crime phase (use of a weapon, use of restraints, use of a vehicle, and level of force used), and the post-crime phase (event leading to the end of crime and victim release site location choice).Beauregard (2007) found that sex offenders, even if traditionally described as “irrational” and impulsive individuals, are capable, up to a certain point, of an analysis of the costs related to their actions.